Tesco has contacted the police after claims customer accounts had been hacked and ClubCard vouchers pilfered.

Customers complained vouchers had gone missing from their rewards accounts. Reports indicated vouchers worth hundreds of pounds had been stolen from those shoppers who had stored up their rewards.

It remains unclear what kind of breach may have taken place and Tesco is keeping schtum on the details.

Tesco initiates investigation

“We have launched a thorough investigation into a small number of incidents and referred the matter to the police,” a Tesco spokesperson said, in an emailed statement sent to TechWeekEurope.

“In the meantime, we’d like to ask any customers who believe they’re affected to contact us directly so that we can make sure their accounts are up to date.”

The incident will do little to appease those frustrated with Tesco security. Last year, security researcher Troy Hunt brought to light various issues with the supermarket giant’s security, most notably that it was sending user passwords in plain text, indicating it wasn’t using proper hashing or other encryption methods to protect user logins.

TechWeekEurope also revealed in July the Tesco website contained an XSS flaw, which could have helped hackers hijack customer accounts by having session cookies sent to attacker-controlled servers.